I started playing WoW in vanilla back in 2006, I was still a kid back then - once cataclysm dropped I'd had time to learn english and understand the basics of the game. Hence Cataclysm was the first expansion I was able to play and understand... With that said it's a big nostalgia thing for me, but I always tend to come back to Cataclysm for it's content and gameplay. So, I guess I would say it's my favourite expansion when compared to all the others.